A motor vehicle comprises a number of wheels which are supported in relation to a body by means of a chassis. The chassis allows a predetermined vertical movement of each wheel in order to keep the wheels in contact with an underlying surface as far as possible and in order to prevent impacts and movements of the body. The body usually comprises a vehicle frame to which further elements of the motor vehicle are fitted, in particular a drive motor and a passenger compartment. The chassis comprises articulation connections of the wheels and usually a dedicated spring and damper unit for each wheel.
A ride height of the body in relation to the wheels or the underlying surface can be determined by wheel heights, which in each case indicate the distance between the body and the wheel, being linked to one another. The ride height of the body can be determined statically, so that a height or an inclination in the longitudinal or lateral direction of the body is determined, or dynamically by a movement of the body upward or downward and also rocking in the longitudinal or lateral direction being determined. The ride height of the body can be determined, in particular, in order to actively influence the chassis. For example, an electronic stability program can acquire information about the height of the center of gravity of the motor vehicle by means of the static or dynamic ride height. The height of the center of gravity can be changed, for example, by a roof load being applied to the motor vehicle. Influencing the chassis such that a situation of the motor vehicle being involved in an accident when traveling quickly around a curve is prevented, can take into account the height of the center of gravity and as a result achieve improved results. The ride height can be used in general by various safety or comfort systems on board the motor vehicle.
Since the ride height of the body can have an influence on a safety-related system of the motor vehicle, the process of determining the ride height has to meet stringent requirements in respect of accuracy or reliability which can be specified, for example, as a stage in the ASIL standard.
WO 2011/098333, which is incorporated by reference herein, A1 describes a vehicle sensor node in which a plurality of sensor elements which detect different primary measurement variables and use different measurement principles are provided. The plausibility of measurement values can be checked in this way.
EP 1 792 759 B1, which is incorporated by reference herein, describes an apparatus in which sensors are provided for ascertaining ride heights. Each sensor can diagnose an individual malfunction and output a corresponding signal. If too many sensors indicate that they are no longer functioning correctly, vehicle height regulation can be stopped.
U.S. Pat. No. 5,627,751, which is incorporated by reference herein, describes a method in which a measurement value of a damaged sensor can be replaced by a calculated signal.